Question

A cylindrical cork is 6 cm high and has a TSA of 33.38 cm2. Could it be used to close a bottle whose neck is 3 cm in diameter? Justify your answer.

Answer 1

sorry but that is the incorrect answer.

Answer 2

TSA = 2pi*r^2 + 2pi*r*h
33.38 = 6.28r^2 + (6.38)(6)*r
33.38 = 6.28r^2 + 37.7r
0 = 6.28r^2 + 37.7r - 33.38
i believe you use quadratic formula and take the positive root

Answer 3

the radius of the bottle is 3/2 = 1.5 so compare that with the radius of the cork

Answer 4

the answers say that the diameter of the cork is 1.6cm though.

Answer 5

I want to know how 1.6cm is achieved.

Answer 6

and the radius of the bottle is indeed 1.5 but we don't need that, we are comparing the diameters.

Answer 7

you can compare diameters but you can also compare radii

Answer 8

since TSA is in terms of radius, i just turned diameter into radius

Answer 9

yep but how is 1.6cm of the diameter of the cork obtained?

Answer 10

like i said use quadratic formula on 6.28r^2 + 37.7r - 33.38 = 0 have you tried that?

Answer 11

tell me when you arrive with an answer. remember to take the positive root

Answer 12

0.78?

Answer 13

k, I get it now, thanks.

Answer 14

you're welcome